Sushruta Samhita
तत्र भ्रूगण्डशङ्खललाटाक्षिपुटौष्ठदन्तवेष्टकक्षाकुक्षिवङ्क्षणेषु तिर्यक् छेद उक्तः ॥१३॥
In cases involving areas such as the eyebrows, cheeks, temples, forehead, eyelids, lips, gums, armpits, abdomen, and groin, it is recommended to make oblique incisions (tiryaṅk cheda). These oblique cuts ensure minimal damage to sensitive structures and promote better healing in regions where straight incisions might cause complications.
english translation
tatra bhrUgaNDazaGkhalalATAkSipuTauSThadantaveSTakakSAkukSivaGkSaNeSu tiryak cheda uktaH ॥13॥
hk transliteration by Sanscript